CN107813892B - travel device - Google Patents

Abstract

The present invention provides a traveling device, which includes an adjustment mechanism, an instruction accepting unit and a control unit, the adjustment mechanism is configured to adjust the wheelbase length between the front wheel and the rear wheel through the action transmitted by the user; the instruction accepting The unit is configured to accept an instruction to travel forward or backward from the user; the control unit is configured to: control the drive unit to drive the traveling device based on the forward target speed when the instruction accepting unit accepts the instruction to travel forward Driving forward, the forward target speed is associated with the wheelbase length in such a way that the longer the wheelbase length, the forward target speed becomes larger, and when the command accepting unit accepts the command to travel backward, based on the relationship with the wheelbase The length-related backward target speed is used to control the drive unit to drive the travel device to travel backward.

Description

travel device

technical field

The present disclosure relates to a travel device on which a user rides and travels.

Background technique

Today, personal mobility vehicles have received attention. Personal mobility vehicles are often manufactured in smaller sizes in view of maneuverability, which causes a problem of their lack of stability when traveling at high speeds. In order to improve the stability of vehicles including but not limited to personal mobility vehicles, vehicles with adjustable wheelbase lengths have been proposed (eg, Japanese Unexamined Patent Application Publication Nos. H1-106717 and 2005-231415).

SUMMARY OF THE INVENTION

So far, personal mobility vehicles have been designed for forward travel, such as those capable of adjusting the length of the wheelbase, but little consideration has been given to backward travel. In personal mobility vehicles with some consideration for backward travel, the operating system for backward travel is independent of that for forward travel. Therefore, these personal mobile vehicles do not allow the user to intuitively acquire the driving operation.

The present disclosure is made to address such a problem, and provides a travel device that provides an intuitive user interface for forward travel and reverse travel.

An exemplary aspect of the present disclosure is a traveling device that includes at least a front wheel and a rear wheel with respect to a traveling direction, and a user rides on the traveling device while traveling. The running device includes: a front wheel support member configured to rotatably support a front wheel; a rear wheel support member configured to rotatably support a rear wheel; and a drive unit that drives The unit is configured to drive at least one of the front and rear wheels; an adjustment mechanism configured to adjust the length of the wheelbase between the front and rear wheels through actions transmitted by the user, thereby changing the front wheel support relative positions of the member and the rear wheel support member; an instruction accepting unit configured to accept an instruction to travel forward or backward from a user; and a control unit configured to: accept at the instruction accepting unit When a forward travel command is given, the drive unit is controlled based on the forward target speed to drive the travel device to travel forward, and the forward target speed and the wheelbase length become larger as the wheelbase length is longer. and the driving unit is controlled to drive the traveling device to travel backwards based on the backward target speed associated with the wheelbase length when the command accepting unit accepts the command to travel backwards.

With this configuration, a simple and intuitive user interface can be achieved, wherein when the user as the occupant moves his/her body to extend or retract the wheelbase length, the running gear begins to pre-indicate along the user driving in the direction.

According to the present disclosure, it is possible to provide a travel device that provides an intuitive user interface for forward travel and reverse travel.

The above and other objects, features and advantages of the present invention will become more fully understood from the detailed description given hereinafter and the accompanying drawings, which are given for purposes of illustration only and are therefore not to be considered limiting this invention.

Description of drawings

FIG. 1 is an overall side view of the traveling apparatus according to the first embodiment when it travels at a low speed;

Figure 2 is an overall top view of the running device;

Figure 3 is a general view of the lever switch from above;

Figure 4 is a general side view of the running device when it is running at a high speed;

5 is a control block diagram of the traveling apparatus according to the first embodiment;

FIG. 6 is a graph showing the relationship between the rotation angle and the target speed;

7 is a table showing a relationship between a rotation angle and a target speed according to another example;

FIG. 8 is a flowchart showing processing when the traveling device travels;

9 is an overall side view of the traveling apparatus according to the second embodiment when it travels at a low speed;

FIG. 10 is a graph showing the relationship between the rotation angle and the target speed; and

11A and 11B are diagrams for describing a change in the length of the WB when the front wheel is braked.

Detailed ways

Hereinafter, although the present disclosure will be described with reference to the embodiments of the present disclosure, the invention according to the claims is not limited to the following embodiments. Furthermore, all the components described in the following embodiments are not necessarily indispensable to the means to solve the problem.

The first embodiment will be described below. FIG. 1 is an overall side view of the traveling apparatus 100 according to the first embodiment when it travels at a low speed. FIG. 2 is a plan view when viewed from above of the traveling device 100 in the state shown in FIG. 1 . The user 900 shown by the dashed line in FIG. 1 is not shown in FIG. 2 .

The travel device 100 is a personal mobile vehicle and is an electrically operated moving vehicle on which a user stands while he or she rides on the travel device 100 . The traveling device 100 includes one front wheel 101 and two rear wheels 102 (right rear wheel 102a and left rear wheel 102b) with respect to the traveling direction. The orientation of the front wheel 101 is changed when the user 900 as the occupant operates the handlebars 115 . The front wheel 101 serves as a steering wheel. The right rear wheel 102a and the left rear wheel 102b are coupled by the axle 103 and driven by a motor and a reduction mechanism (not shown). The right rear wheel 102a and the left rear wheel 102b serve as drive wheels. The running device 100 is grounded at three points by three wheels and is a stationary stable vehicle that is self-supporting even when the running device 100 is parked without the user 900 riding on it.

The front wheel 101 is rotatably supported by the front wheel support member 110 . The front wheel support member 110 includes a front rod 111 and a fork 112 . The fork 112 is fixed to one end of the front rod 111 and sandwiches the front wheel 101 to rotatably support the front wheel 101 on both sides of the front wheel 101 . The handlebar 115 extends in the direction of the rotation axis of the front wheel 101 , and the handlebar 115 is fixed to the other end portion of the front rod 111 . When the user 900 turns the handlebar 115 , the front lever 111 transmits an operating force to the front wheel 101 to change the orientation of the front wheel 101 .

The rear wheel 102 is rotatably supported by a rear wheel support member 120 . The rear wheel support member 120 includes a rear rod 121 and a body portion 122 . The body portion 122 fixes and supports one end portion of the rear lever 121, and the body portion 122 rotatably supports the right and left rear wheels 102a and 102b through the axle 103 interposed between the right and left rear wheels 102a and 102b. The body portion 122 also serves as a housing that houses the above-described motor and reduction mechanism, a battery that supplies power to the motor, and the like. A pedal 141 is provided on the upper surface of the body portion 122 for the user 900 to place his or her feet.

The front wheel support member 110 and the rear wheel support member 120 are coupled to each other by a pivot joint 131 and a hinge joint 132 interposed between the front wheel support member 110 and the rear wheel support member 120 . The pivot joint 131 is fixed to the front lever 111 at a position near the other end of the front lever 111 to which the handlebar 115 is fixed, wherein the front lever 111 constitutes the front wheel support member 110 . Furthermore, the pivot joint 131 is pivotally arranged on the hinge joint 132 and rotates relative to the hinge joint 132 about _a pivot axis _TA which is arranged parallel to the direction in which the front lever 111 extends. The hinge joint 132 is pivotally arranged on one end of the rear lever 121 constituting the rear wheel supporting member 120 , which is opposite to the end of the rear lever 121 supported by the body portion 122 . The hinge joint 132 rotates relative to the rear lever 121 about _a hinge axis _HA which is arranged parallel to the direction in which the axle 103 extends.

With this configuration, when the user 900 turns the handlebar 115, the front wheel support member 110 rotates about the pivot axis _TA relative to the rear wheel support member 120 so that the orientation of the front wheel 101 can be changed. Further, when the user 900 tilts the handlebar 115 forward in the traveling direction in which the traveling device 100 travels forward, the tilting action is transmitted to the front wheel supporting member 110 and the rear wheel supporting member 120, so that the front wheel supporting member 110 and the rear wheel The support members 120 are rotated relative to each other about the hinge axis _HA so that the angle formed by the front rod 111 and the rear rod 121 can be smaller. When the angle formed by the front rod 111 and the rear rod 121 is small, the WB length, which is the distance of the wheelbase (WB) between the front wheel 101 and the rear wheel 102, will become shorter. Conversely, when the user 900 tilts the handlebar 115 rearward in the traveling direction in which the traveling device 100 is traveling forward, the front wheel supporting member 110 and the rear wheel supporting member 120 rotate relative to each other about the hinge axis _HA so that the front The angle formed by the rod 111 and the rear rod 121 may be increased. As the angle formed by the front rod 111 and the rear rod 121 increases, the WB length increases. That is, the user 900 can decrease or increase the WB length by performing an action as a rotational force.

A biasing spring 133 is attached around the hinged joint 132 . The biasing spring 133 is, for example, a torsion spring. The biasing force of the biasing spring 133 is exerted on the hinge axis _HA and changes the angle formed by the front lever 111 and the rear lever 121 to the reference rotation angle when the user 900 is not in contact with the handlebar 115 . On the other hand, the biasing force of the biasing spring 133 is configured to such an extent that the user 900 can easily tilt the handlebar 115 rearward in the running direction. Accordingly, the user 900 can adjust the angle formed by the front rod 111 and the rear rod 121 and thus the WB length by changing at least one of the weight on the handlebar 115 and the weight on the pedals 141 . That is, the mechanism for connecting the front lever 111 to the rear lever 121 through the hinge joint 132 interposed between the front lever 111 and the rear lever 121 serves as an adjustment mechanism for the user 900 to adjust the length of the WB.

A rotation angle sensor 134 is attached around the hinge joint 132 . The rotation angle sensor 134 outputs the angle formed by the front lever 111 and the rear lever 121 about the hinge axis _HA . That is, the rotation angle sensor 134 functions as a measurement unit for measuring the relative positions of the front wheel supporting member 110 and the rear wheel supporting member 120 . The rotation angle sensor 134 is, for example, a rotary encoder. The output from the rotation angle sensor 134 is sent to a control unit which will be described later.

A lever switch 116 is provided near the center of the handlebar 115 . FIG. 3 is a general view of the lever switch 116 as seen from above the travel device 100 . The lever switch 116 is an operating member serving as an instruction accepting unit that accepts an instruction from the user 900 to move the traveling apparatus 100 forward or backward.

The lever switch 116 mainly includes a panel 116a, a sliding groove 116b and a lever 116c. The two positions "forward" and "backward" are printed on panel 116a. The user 900 can grasp the lever 116c and slide the lever 116c along the slide slot 116b to leave the lever 116c in the "forward" or "backward" position. A control unit, which will be described later, detects the position of the lever 116c and determines whether to move the traveling device 100 forward or backward. This will be described in detail later. It should be noted that the operating member as the command accepting unit is not limited to the lever switch, but may be another operating member as long as it can selectively instruct "forward" or "backward". For example, the operation member may be a button or a touch panel.

The traveling apparatus 100 of the present embodiment travels at a low speed when the WB length is short, and travels at a high speed when the WB length is long, regardless of whether it travels forward or backward. FIG. 1 shows a state in which the traveling apparatus 100 having a short WB length is traveling at a low speed. FIG. 4 is a general side view of the traveling apparatus 100 shown in FIG. 1 , and FIG. 4 shows a state in which the traveling apparatus 100 having a long WB length is traveling at a high speed.

As shown in the figure, the direction in which the angle formed by the front rod 111 and the rear rod 121 is relatively increased is positive, and the rotation angle is θ. Further, the minimum value (minimum angle) that the rotation angle θ can take is θ _MIN , and the maximum value (maximum angle) that the rotation angle θ can take is θ _MAX . For example, θ _MIN is 10 degrees and θ _MAX is 80 degrees. In other words, the structural control member is provided such that the rotation angle θ falls within the range between θ _MIN and θ _MAX .

The WB length has a one-to-one correspondence with the rotation angle θ, and the WB length can be calculated by the following function: WB length=f(θ). Therefore, the WB length can be adjusted by changing the rotation angle θ. The traveling device 100 in the present embodiment accelerates when the user 900 increases the rotation angle θ, and the traveling device 100 decelerates when the user 900 decreases the rotation angle θ. That is, the target speed is associated with the rotation angle θ, and a change in the rotation angle θ accelerates/decelerates the traveling device 100 to reach the target speed associated with the changed rotation angle θ.

When the rotation angle θ decreases, the WB length becomes shorter, thereby improving the maneuverability. That is, the traveling device 100 can be moved around in a small space. Conversely, as the rotation angle θ increases, the WB length becomes longer, thereby improving the running stability, especially the straight driving performance. That is, even when the traveling device 100 is traveling at a high speed, it is not easily affected by the sway caused by bumps or the like on the road. Since the WB length changes in conjunction with changes in speed, the WB length will not be long when the travel device 100 travels at low speed, and thus the travel device 100 can move in the smallest projected area at low speed. That is, the area of the road required for the traveling device 100 to travel is small, and an excessive area is not required. Since the user 900 can change both the speed and the WB length in conjunction with each other when he/she tilts the handlebar 115 forward and backward, the driving operation is easy and simple.

Since the WB length is adjusted by transmitting the force generated by the actions of the user 900, an actuator for adjusting the WB length is not required. Therefore, the weight of the traveling device 100 according to the present embodiment is reduced as a whole. Therefore, unlike the personal mobile vehicle of the related art, the traveling device 100 of the present embodiment can provide, for example, the convenience that the user 900 can easily bring it into the train.

Next, the system configuration of the traveling device 100 will be described. FIG. 5 is a control block diagram of the traveling device 100 . The control unit 200 is, for example, a CPU and is accommodated in the body portion 122 . The drive wheel unit 210 includes a drive circuit and a motor for driving the rear wheels 102 as drive wheels. The drive wheel unit 210 is accommodated in the body portion 122 . The control unit 200 transmits a driving signal to the driving wheel unit 210 , thereby controlling the rotation of the rear wheel 102 .

The vehicle speed sensor 220 monitors the rotation amount of the rear wheel 102 or the axle 103 and detects the speed of the traveling device 100 . In response to a request from the control unit 200, the vehicle speed sensor 220 transmits the detection result to the control unit 200 as a speed signal. The rotation angle sensor 134 detects the rotation angle θ in the above-described manner. In response to a request from the control unit 200, the rotation angle sensor 134 transmits the detection result to the control unit 200 as a rotation angle signal.

The load sensor 240 is, for example, a piezoelectric film that detects a load applied to the pedal 141 , and the load sensor 240 is embedded in the pedal 141 . In response to a request from the control unit 200, the load sensor 240 transmits the detection result to the control unit 200 as a load signal.

As described above, in response to a request from the control unit 200, the lever switch 116 sends a detection signal to the control unit 200 indicating whether the lever 116c is in the "forward" position or the "rearward" position. Based on the received detection signal, the control unit 200 determines whether the drive signal to be sent to the drive wheel unit 210 is a forward rotation signal for rotating the motor forward or a backward rotation signal for rotating the motor backward.

The memory 250 is a non-volatile storage medium and is, for example, a solid state drive. The memory 250 stores not only a control program for controlling the traveling device 100 but also various parameter values, functions, look-up tables, and the like for control. The memory 250 stores a conversion table 251 for converting the rotation angle to the target speed.

FIG. 6 is a diagram showing the relationship between the rotation angle θ and the target speed as an example of the conversion table 251 for converting the rotation angle θ into the target speed. In FIG. 6 , the horizontal axis represents the rotation angle θ (degrees), and the vertical axis represents the target speed (km/h). In FIG. 6 , the linear function shown as “forward” represents the forward target speed relative to the rotation angle θ applied when the lever switch 116 indicates “forward”. In addition, the linear function shown as "backward" represents the backward target speed relative to the rotation angle θ that is applied when the lever switch 116 indicates "backward". These target speeds are expressed by positive values that are travel distances per unit time, regardless of whether the travel apparatus 100 travels forward or backward.

The forward target speed is configured to become larger as the rotation angle θ increases, that is, the forward target speed is configured to become larger as the WB length becomes longer. The target velocity is zero at the minimum angle θ _MIN (degrees) and the target velocity is V _m (km/h) at the maximum angle θ _MAX (degrees). The backward target speed is also configured to become larger as the rotation angle θ increases, that is, the backward target speed is also configured to become larger as the WB length becomes longer. The target velocity is zero at the minimum angle θ _MIN (degrees), and the target velocity is V _m /2 (km/h) at the maximum angle θ _MAX (degrees). In this case, the maximum target speed in the case of backward travel is configured to be half the maximum target speed in the case of forward travel. However, these maximum speeds can be arbitrarily configured according to the performance of the traveling device 100 or the like. In consideration of traveling efficiency and posture stability when the user 900 rides on the traveling device 100 , the maximum target speed in the case of backward traveling is preferably configured to be smaller than the maximum target speed in the case of forward traveling.

When the lever switch 116 is positioned at “forward”, the control unit 200 determines the forward target speed based on the current rotation angle θ adjusted by the user 900 and transmits a drive signal for forward rotation to the drive wheel unit 210 , so that the current speed follows the target speed. Likewise, when the lever switch 116 is positioned "backward", the control unit 200 determines the target speed backward based on the current rotation angle θ adjusted by the user 900, and transmits a drive signal for backward rotation to the drive wheels Unit 210, so that the current speed follows the target speed.

In this way, if the rotation angle θ and the target speed can be related by a function, the conversion table 251 can be described in the form of a function. The conversion table 251 described in the form of a function is stored in the memory 250, and the conversion table 251 is appropriately referred to.

FIG. 7 is a table showing the relationship between the rotation angle θ and the target speed as another example of the conversion table 251 for converting the rotation angle θ into the target speed. In the example of FIG. 7 , the continuously varying rotation angle θ is divided into groups, and each group is associated with a forward target speed and a backward target speed. It should be noted that the target speed is expressed by a positive value that is a travel distance per unit time, regardless of whether the travel apparatus 100 travels forward or backward.

As shown in FIG. 7, regarding the forward target speed, the target speed 0 (km/h) is associated with the group in which the rotation angle θ is in the range between θ _MIN or more and less than θ ₁ , the target speed 5.0 (km/h) /h _{) Associated with the group in which the rotation angle θ is in the range of θ 1 or more} and less _than Groups are associated, and a target speed of 15.0 (km/h) is associated with groups where the rotation angle θ is within a range _of θ3 or more and less than _θMAX . Further, with regard to the backward target speed, the target speed 0 (km/h) is associated with a group in which the rotation angle θ is in the range between θ _MIN or more and less than θ ₁ , and the target speed 2.5 (km/h) is associated with the rotation An angle θ of θ ₁ or more is associated with a group within a range less than θ ₂ , a target speed of 5.0 (km/h) is associated with a rotation angle θ of θ ₂ or greater and a group within a range of less than θ ₃ , and the target A speed of 7.5 (km/h) is associated with a group in which the rotation angle θ is within the range of θ ₃ or more and less than θ _MAX . It should be noted that in this case, in all groups, the backward target speed was configured to be half the forward target speed. However, these target speeds may be arbitrarily configured according to the performance of the traveling device 100 or the like.

The conversion table 251 in this case may take the form of a lookup table. As in the above example, when the target speed is associated with a slightly wider range of the rotation angle θ, the target speed does not change little by little due to, for example, being affected by the swing of the body of the user 900, and thus it can be expected The speed will change smoothly. Obviously, hysteresis may be included in the boundaries between the above ranges of rotation angles, and by setting different boundaries of the ranges of these angles during acceleration and deceleration, it is expected that the speed will change more smoothly.

The association between the rotation angle θ and the target speed is not limited to the examples of FIGS. 6 and 7 , and various other associations may be formed. As an example of association, the change amount of the target speed corresponding to the change amount of the rotation angle θ may be configured to be small in the low speed region, and the change amount of the target speed corresponding to the change amount of the rotation angle θ may be configured to be small in the high speed region Medium and larger. Further, in the present embodiment, although the conversion table 251 for associating the rotation angle θ as a parameter with the target speed is employed because the rotation angle θ corresponds to the WB length one-to-one, it may alternatively be based on the original The purpose is to employ a conversion table for associating WB length with target speed. In this case, the rotation angle θ obtained by the rotation angle sensor 134 may be converted into the WB length by using the above function, and the conversion table may be referred to.

Next, the running process according to the present embodiment will be described. FIG. 8 is a flowchart showing processing executed while the traveling device 100 is traveling. The flow starts when the power switch is turned on and a signal indicating the presence of a load is received from the load sensor 240 , that is, when the user 900 rides on the traveling device 100 .

In step S101 , the control unit 200 checks the lever position of the lever switch 116 . When the lever position is the "forward" position, the control unit 200 performs forward control, and when the lever position is in the "backward" position, the control unit 200 performs backward control.

The control unit 200 proceeds to step S102, obtains the rotation angle signal from the rotation angle sensor 134, and calculates the current rotation angle θ. In step S103, the calculated rotation angle θ is applied to the conversion table 251 that has been read out from the memory 250 to set the forward target speed or the backward target speed according to the check result in step S101.

When the control unit 200 sets the target speed, the control unit 200 proceeds to step S104 and transmits a drive signal of acceleration or deceleration to the drive wheel unit 210 . Specifically, the control unit 200 first receives a speed signal from the vehicle speed sensor 220 and checks the current speed. If the target speed is greater than the current speed, the control unit 200 transmits an accelerated driving signal to the driving wheel unit 210 , and if the target speed is less than the current speed, the control unit 200 transmits a decelerated driving signal to the driving wheel unit 210 .

The control unit 200 monitors whether the rotation angle ? has changed during acceleration or deceleration (step S105). If the control unit 200 determines that the rotation angle θ has changed, the control unit 200 causes the process to start from step S102 again. If the control unit 200 determines that the rotation angle θ has not changed, the control unit 200 proceeds to step S106. It should be noted that when the conversion table shown in FIG. 7 is employed, if the change of the rotation angle θ is within one group, it is determined that the rotation angle θ has not changed.

In step S106, the control unit 200 receives the speed signal from the vehicle speed sensor 220 and evaluates whether the current speed has reached the target speed. If the control unit 200 determines that the current speed has not reached the target speed, the control unit 200 returns to step S104 and continues to accelerate or decelerate. If the control unit 200 determines that the current speed has reached the target speed, the control unit proceeds to step S107. In step S107, the control unit 200 checks whether the target speed is zero. If the target speed is zero, it means that the traveling device 100 is stopped at step S107. Otherwise, the traveling device 100 is traveling at the target speed, and thus the control unit 200 sends a drive signal to the drive wheel unit 210 to keep the traveling device 100 traveling at this speed (step S108 ).

Even when the traveling device 100 is traveling at a constant speed in step S108, the control unit 200 monitors whether the rotation angle ? has changed (step S109). If the control unit 200 determines that the rotation angle θ has changed, the control unit 200 returns to step S102. If the control unit 200 determines that the rotation angle θ has not changed, the control unit 200 returns to step S108 to continue traveling at a constant speed.

If the control unit 200 confirms that the target speed is zero in step S107 , the control unit 200 proceeds to step S110 and evaluates whether the user 900 leaves the traveling device 100 based on the load signal received from the load sensor 240 . If the control unit 200 determines that the user 900 has not left the traveling device 100, that is, that the load is present, the control unit 200 returns to step S101 to continue the traveling control. The control unit 200 returns to step S101 because the lever switch 116 accepts the operation of the user 900 when the speed becomes zero in step S107. The control unit 200 returns to step S101 in order to check whether the lever switch 116 is operated by the user 900 and whether the traveling direction is reversed.

In the present embodiment, the lever switch 116 is only operated when the speed of the traveling device 100 becomes zero, not when the traveling device 100 is traveling. Since the operation of the lever switch 116 is not accepted until the speed becomes zero as described above, it is possible to prevent the backward rotation drive signal from being sent while the drive wheels are rotating, thereby preventing an excessive load from being applied to the driving system. The lever switch 116 is configured as follows, for example. When a travel signal is being received, the lever 116c is locked to prevent the lever 116c from sliding. When the speed becomes zero and the travel signal stops, the lever 116c is unlocked, enabling the lever 116c to slide. If the operating member is a button instead of a lever switch, when the speed is zero, the button can be illuminated to indicate that an instruction to reverse the direction can be given, and the button can only be illuminated to accept a message from the user 900 instruction.

The speed at which the lever switch 116 accepts operation may, for example, be specified as a certain speed range, such as a speed range of less than 1.0 km/h, in which the load on the driving system is acceptable. In other words, it can be configured in such a way that if the speed is not less than the predetermined speed, the operation is not accepted. Further, in the present embodiment, the condition under which the lever switch 116 accepts the operation is defined by the speed using the output of the vehicle speed sensor 220 . However, such conditions can be defined based on other parameters. For example, WB length can be used as this parameter. In this case, it may be configured in such a manner that when the detected current WB length is not less than the predetermined WB length, the operation of the operation member is not accepted.

In step S110, if the control unit 200 determines that the user 900 has left the traveling device 100, the series of operations ends. The control unit 200 turns off the travel device 100 .

Next, the second embodiment will be described. FIG. 9 is an overall side view of the traveling apparatus 600 according to the second embodiment when it travels at a low speed. The running device 600 is mainly different from the running device 100 of the first embodiment in that the front wheel 101 includes a disc brake 117 and the target speed in the rear is constant. Elements of the traveling device 600 according to the second embodiment that have the same functions as those of the traveling device 100 of the first embodiment are denoted by the same reference numerals as those in the first embodiment. Therefore, the description of these elements will be omitted here. In addition, the control block configuration and processing flow of the traveling device 600 are almost the same as those of the traveling device 100 . Therefore, in the following description, only the differences between the traveling device 600 and the traveling device 100 are mainly focused.

The front wheel 101 includes a disc brake 117 as a braking member, which brakes the rotation of the front wheel 101 . In the disc brake 117 , in response to a signal from the control unit 200 , the brake pads 117 b are used to clamp the disc 117 a attached to the inside of the wheel to generate friction, thereby reducing the rotational speed of the front wheel 101 .

FIG. 10 is a diagram showing the relationship between the rotation angle and the target speed in this embodiment; in FIG. 10 , the horizontal axis represents the rotation angle θ (degrees), and the vertical axis represents the target speed (km/h). In FIG. 10 , the linear function shown as “forward” represents the forward target speed relative to the rotation angle θ applied when the lever switch 116 indicates “forward”. In addition, the linear function shown as "backward" represents the backward target speed relative to the rotation angle θ that is applied when the lever switch 116 indicates "backward". It should be noted that these target speeds are expressed by positive values that are travel distances per unit time, regardless of whether the travel device travels forward or backward.

As in FIG. 6 , the forward target speed is configured to become larger as the rotation angle θ increases, that is, the forward target speed is configured to become larger as the WB length becomes longer. The target velocity is zero at the minimum angle θ _MIN (degrees) and the target velocity is V _m (km/h) at the maximum angle θ _MAX (degrees). When the rotation angle θ is the minimum value θ _MIN , the backward target speed is zero, and when the rotation angle θ is greater than the minimum value θ _MIN , the backward target speed is a constant value V _c (km/h).

That is, in the case where the traveling device 600 travels forward, when the rotation angle θ increases and the WB length becomes longer, the target speed increases proportionally. However, in the case where the traveling device 600 travels backward, the target speed remains constant even if the WB length becomes longer. Depending on the purpose of use of the traveling device 600, there are cases where it is not necessary to travel at a high speed when traveling backward. In this case, it is preferable to configure the running device 600 so that the backward speed remains the same, thereby focusing on stability. Furthermore, in the case where the traveling device 600 travels backward, the user 900 may easily lose his/her balance while driving while he/she often turns back. However, if the WB length increases when the traveling device 600 travels backwards, there is no such concern. In the present embodiment, since the backward speed does not increase even if the WB length increases, the user 900 can easily maintain his/her balance

In the present embodiment, the traveling device 600 extends the WB length so that the user 900 can easily maintain his/her balance without deliberately adjusting the adjustment mechanism. 11A and 11B are diagrams for describing a change in the length of the WB when the front wheel is braked.

When the traveling device 600 travels backward, the control unit 200 activates the disc brake 117 . More specifically, the control unit 200 does not completely stop the rotation of the front wheel 101 by the disc brake 117, but the control unit 200 depresses the rotation of the front wheel 101 so as to reduce the rotation speed of the front wheel 101 to be smaller than that of the rear wheel, which is a driving wheel. The rotational speed of the wheel 102 .

FIG. 11A shows the state of the traveling device 600 when it starts traveling backward. Since it is the time when the traveling device 600 starts traveling backward, as described above, the rotation angle θ is the minimum value θ _MIN , and the WB length is the minimum value WB _MIN . When the rear wheel 102 starts to rotate backward in this state, the traveling device 600 starts traveling backward. At the same time, however, the braking of the disc brake 117 is also started.

Then, the rotation speed of the front wheel 101 becomes smaller than the rotation speed of the rear wheel 102, the front rod 111 and the rear rod 121 start to rotate relative to each other about the hinge axis _HA , and the rotation angle θ gradually increases. FIG. 11B shows the state of the traveling device 600 at a certain point in time after the traveling device 600 starts traveling backward. As shown in FIG. 11B , the rotation angle θ becomes V _c greater than θ _MIN , and the WB length also extends to WB _c . When the disc brake 117 is activated with the running device 600 traveling backwards in this manner, the WB length is naturally extended without the user 900 operating the handlebars while he/she is looking backwards. Therefore, the user 900 is less likely to lose his/her balance.

In the present embodiment, the disc brake 117 is used as a braking member that brakes the rotation of the front wheel 101 when the traveling device 600 travels backward. However, the disc brake 117 may be another member as long as it imparts rotational resistance to the front wheel 101 . For example, the disc brake 117 may be a one-way rotational damper that only works when the front wheel 101 is rotated rearward. In addition, the disc brake 117 can be used as a brake when the traveling device 600 is traveling forward. In this case, preferably, a brake lever is provided on the handle 115 so that the disc brake 117 is activated when the user grasps it.

So far, the first embodiment and the second embodiment have been described. A conversion table for setting the target speed to a constant value when the traveling device that has been described with reference to FIG. 10 in the second embodiment travels backwards may be employed in the traveling device 100 according to the first embodiment. If it is not necessary to drive backwards at a high speed, it is desirable to drive backwards at a constant low speed. It may be configured such that the user as the occupant can select a conversion table on how to set the target speed when the traveling device is traveling backwards.

The front and rear wheels may not be wheels, but may be grounded elements such as ball wheels, tracks, or the like. Furthermore, the power source for driving the drive wheels is not limited to the motor, but may be a gasoline engine or the like.

From the invention thus described, it will be apparent that the embodiments of the invention may be varied in many ways. Such modifications are not to be considered as a departure from the spirit and scope of the invention, and all such modifications apparent to those skilled in the art are intended to be included within the scope of the appended claims.

Claims (7)

1. A traveling device comprising at least a front wheel and a rear wheel with respect to a traveling direction, and a user rides on the traveling device when traveling, the traveling device comprising: a front wheel support member configured to rotatably support the front wheel; a rear wheel support member configured to rotatably support the rear wheel; a drive unit configured to drive at least one of the front wheel and the rear wheel; an adjustment mechanism interposed between the front wheel support member and the rear wheel support member and configured to transmit a user's motion to the front wheel support member and/or the rear wheel support member to adjust the wheelbase length between the front wheel and the rear wheel, thereby changing the relative position of the front wheel support member and the rear wheel support member; an instruction accepting unit configured to accept an instruction to travel forward or backward from the user; and a control unit configured to control the drive unit to drive the traveling device to drive forward based on a forward target speed when the instruction accepting unit accepts an instruction to travel forward, the forward travel The target speed of is associated with the wheelbase length in such a way that the forward target speed becomes larger as the wheelbase length is longer; and when the command accepting unit accepts an instruction to travel backward, based on the The rearward target speed associated with the wheelbase length is used to control the drive unit to drive the travel device to travel backwards. 2 . The traveling apparatus according to claim 1 , wherein the rearward target speed is associated with the wheelbase length in such a manner that the rearward target speed becomes larger as the wheelbase length becomes longer. 3 . . 3 . The traveling device according to claim 1 , wherein the backward target speed and the wheelbase length are fixed with the backward target speed being a fixed speed except when the wheelbase length is the shortest. 4 . way related. 4. The running device of claim 3, further comprising a braking member configured to brake rotation of the front wheel, wherein the drive unit drives the rear wheel. 5. The traveling apparatus according to any one of claims 1 to 4, wherein the instruction accepting unit does not accept an instruction when the wheelbase length is not less than a predetermined length. 6. The traveling device according to any one of claims 1 to 4, wherein the instruction accepting unit does not accept an instruction when the speed of the traveling device is not less than a predetermined speed. 7. The traveling device according to claim 5, wherein the instruction accepting unit does not accept an instruction when the speed of the traveling device is not less than a predetermined speed.

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